Popular Mechanics (South Africa)

Defiant vs Valor:

INSIDE THE HEAD-TO-HEAD BATTLE TO REPLACE THE BLACK HAWK

- BY ERIC TEGLER

Inside the head-to-head battle to replace the Black Hawk helicopter.

In 2022, the US Army will choose a new aircraft to replace the Sikorsky UH-60 Black Hawk helicopter. Bell’s V-280 Valor and Sikorsky-Boeing’s SB-1 Defiant will battle it out to become the winner of the Future Long-Range Assault Aircraft (FLRAA) programme, and either the Valor or the Defiant will fly as the army’s next combat helo when it deploys in 2030. But ‘helicopter’ isn’t even the right word to describe these two aerial beasts. Bell’s V-280 Valor is a tilt-rotor, similar to the V-22 Osprey currently flown by the US Marine Corps, Air Force, and Navy, but smaller and with a V-tail. Rather than relying on a single large main rotor for lift in forward flight and vertical take-off and landing (VTOL) like a helicopter, it tilts two large rotors (called proprotors), one at each of its wing tips, 90° from horizontal to vertical and back. It’s essentiall­y an aeroplane in forward flight and a twin-rotor helicopter in VTOL flight.

Meanwhile, Sikorsky-Boeing’s SB-1 Defiant is a compound helicopter, with stacked, counter-rotating main rotors, a pusher-propeller, and aircraft-like rudders. The pusher-propeller can provide significan­t forward thrust, relieving the need to tilt its main rotor for forward flight. Counter-rotating main rotors provide extra lift, stability, and smoothness. They also give the SB-1 speed, climb, and VTOL advantages over normal helicopter­s.

Both designs stem from the US Army’s desire for a multimissi­on VTOL aircraft that flies much faster and further than the workhorse Black Hawk. The army wants its UH-60 replacemen­t to be capable of a top speed of 230 knots (425 km/h) – a twin-engine Black Hawk tops out at 159 knots (295 km/h).

Despite it being four decades old, bettering the Black Hawk won’t be easy. The helicopter has been built in two dozen variants for the army alone.

‘The Black Hawk is a tall bar,’ says US Army veteran helicopter pilot and Sikorsky test pilot Bill Fell. ‘We’ve been building them for more than 40 years. In my view it’s the greatest helicopter the world has ever known.’

 ??  ?? Sikorsky-Boeing‘s SB-1 Defiant
Sikorsky-Boeing‘s SB-1 Defiant
 ??  ?? Bell‘s V-280 Valor
Bell‘s V-280 Valor

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